s-Block Elements PYQs Set 5 (PDF)

Set 5 of 20 · Questions 121-150 of 573

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Mere Teacher · Previous Year Questions NEET Chemistry · s-Block Elements · Set 5 (Q121-150)
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121. $The correct order of electrical conductivity of alkali metals ions in their aqueous solution for Cs^{+}, K^{+}, Na^{+} and Li^{+} is$ (1) $Cs^{+} > K^{+} > Na^{+} > Li^{+}$ (2) $K^{+} > Cs^{+} > Li^{+} > Na^{+}$ (3) $Cs^{+} > K^{+} > Li^{+} > Na^{+}$ (4) $Li^{+} > Na^{+} > K^{+} > Cs^{+}$ 122. $What would happen when a solution of potassium chromate is treated with an excess of dilute nitric acid ?$ (1) $C r^{3 +} and C r_{2} O_{7}^{2-} are formed$ (2) $C r_{2} O_{7}^{2-} and H_{2} O are formed$ (3) $CrO_{4}^{2-} is reduced to + 3 state of Cr$ (4) $CrO_{4}^{2-} is oxidized to + 7 state of Cr$ 123. $What would be the product of following reaction? SiCl_{4} \to excess of H 2 O ? (Major product)$ (1) $SiCl_{3} (OH)$ (2) $Si (OH)_{4}$ (3) $SiCl_{2} (OH)_{2}$ (4) $SiCl_{4} (no reaction)$ 124. $The magnetic behaviour of L i_{2} O, N a_{2} O_{2} and K O_{2}, respectively, are$ (1) $diamagnetic, paramagnetic and diamagnetic$ (2) $paramagnetic, paramagnetic and diamagnetic$ (3) $paramagnetic, diamagnetic and paramagnetic$ (4) $diamagnetic, diamagnetic and paramagnetic$ 125. $Which of the following is the strongest reducing agent?$ (1) $TeO_{3}$ (2) $SO_{3}$ (3) $TeO_{2}$ (4) $SO_{2}$ 126. $Several blocks of magnesium are fixed to the bottom of a ship to :$ (1) $make the ship lighter$ (2) $prevent action of water and salt$ (3) $prevent puncturing by under-sea rocks$ (4) $keep away the sharks.$ 127. $The correct order of acidity of HClO, HBrO and HIO is$ (1) $HIO > HBrO > HClO$ (2) $HBrO > HIO > HClO$ (3) $HClO > HBrO > HIO$ (4) $HIO > HClO > HBrO$ 128. $Excess of PCl_{5} reacts with conc. H_{2} SO_{4} giving$ (1) $sulphuryl chloride$ (2) $sulphurous acid$ (3) $chlorosulphonic acid$ (4) $thionyl chloride.$ 129. $Addition of H_{2} S O_{4} to B a O_{2} produces:$ (1) $BaO, S O_{2} and H_{2} O$ (2) $B a H S O_{4} and O_{2}$ (3) $B a S O_{4}, H_{2} and O_{2}$ (4) $B a S O_{4} and H_{2} O_{2}$ 130. $Consider the following statements about the oxides of halogens A. At room temperature, OF_{2} is thermally stable B. Order of stability of oxides of halogens is I > Br > Cl C. I_{2} O_{5} is used in the estimation of CO D. ClO_{2} is used as a bleaching agent The correct statement are.$ (1) $A & B only$ (2) $A,B & only$ (3) $B & C only$ (4) $A, C & D only$ 131. $Which one of the following statements is not correct regarding phosphine?$ (1) $It is a weak base$ (2) $It reacts with CuSO_{4} solution to form CuHPO_{4}$ (3) $It is formed by the reaction of Ca_{3} P_{2} with HCl$ (4) $It is used in smoke screens$ 132. $Which one of the following compounds is having maximum 'lone pair-lone pair' electron repulsions?$ (1) $ClF_{3}$ (2) $IF_{5}$ (3) $SF_{4}$ (4) $XeF_{2}$ 133. $Statement I: An alloy of lithium and magnesium is used to make aircraft plates. Statement II : The magnesium ions are important for cell-membrane integrity. choose the correct answer from the options given below$ (1) $Both Statement I and Statement II are true$ (2) $Both Statement I and Statement II are false$ (3) $Statement I is true but Statement II is false$ (4) $Statement I is false but Statement II is true$ 134. $Bond enthalpy of Ge - Ge bond is 260 kJ mol^{- 1} . The bond enthalpies of Si - Si and Sn - Sn bonds in kJ mol^{- 1} are respectively.$ (1) $240,270$ (2) $297,297$ (3) $297,240$ (4) $200,348$ 135. $On heating with concentrated NaOH solution in an inert atmosphere of CO_{2}, white phosphorus gives a gas. Which of the following statements is incorrect about the gas?$ (1) $It is more basic than NH_{3} .$ (2) $Its solution in water decomposes in the presence of light.$ (3) $It is less basic than NH_{3} .$ (4) $It is highly poisonous and has smell like rotten fish.$ 136. $Thermodynamically most stable allotrope of carbon is$ (1) $Graphite$ (2) $Diamond$ (3) $Fullerene$ (4) $Coke$ 137. $Which one of the following alkaline earth metal sulphates has its hydration enthalpy greater than its lattice enthalpy ?$ (1) $CaSO4$ (2) $BeSO4$ (3) $BaSO4$ (4) $SrSO4$ 138. $The correct statements are: I. The low solubility of LiF is due to its high lattice enthalpy. II. LiBr is not soluble in acetone. III. LiCl is soluble in pyridine. IV. The order of melting points of alkali metal halides is MF > MCl > MBr > MI .$ (1) $I, II and III$ (2) $II, III and IV$ (3) $I, II and IV$ (4) $I, III and IV$ 139. $Which of the following has largest size?$ (1) $Na$ (2) $N a^{+}$ (3) $N a^{-}$ (4) $Can’t be predicted.$ 140. $The number of water molecules in gypsum, dead burnt plaster and plaster of paris, respectively are:$ (1) $2,0 and 1$ (2) $0.5, 0 and 2$ (3) $5, 0 and 0.5$ (4) $2, 0 and 0.5$ 141. $Which of the following statements are not correct? i. Atomic radius of Ga is less than that of Al ii. The order of ionization enthalpy of group elements is B > Al > Ga > In > Tl iii. Boron trioxide is amphoteric in nature$ (1) $ii, iii only$ (2) $i, iii only$ (3) $i, ii only$ (4) $i, ii, iii$ 142. $Which of the following reactions are correct with respect to the formation of products? I. 2 NaOH + SO_{2} ⟶ Na_{2} SO_{4} + H_{2} II. 2 XeF_{4} + 3 O_{2} F_{2} \to 143 K 2 XeO_{3} + 7 F_{2} III. PCl_{5} + 4 H_{2} O ⟶ H_{3} PO_{4} + 5 HCl IV. 2 NaNO_{2} + 2 HCl ⟶ 2 NaCl + NO + NO_{2} + H_{2} O$ (1) $II, IV$ (2) $III, IV$ (3) $I, III$ (4) $II, III$ 143. $A hydrated solid X on heating initially gives a monohydrated compound Y. Y upon heating above 373 leads to an anhydrous white powder Z. X and Z, respectively, are:$ (1) $Washing soda and soda ash.$ (2) $Baking soda and dead burnt plaster.$ (3) $Washing soda and dead burnt plaster.$ (4) $Baking soda and soda ash.$ 144. $X reacts with dilute nitric acid to form 'laughing gas'. What is X ?$ (1) $Cu$ (2) $P_{4}$ (3) $S_{8}$ (4) $Zn$ 145. $Identify the incorrect statement about the interhalogen compounds$ (1) $ICl is more reactive than I_{2}$ (2) $They are diamagnetic in nature$ (3) $The products of ICl and water are HI + HOCl$ (4) $They act as fluorinating agents$ 146. $Sulphur on boiling with NaOH solution forms$ (1) $Na_{2} S_{2} O_{3} + Na_{2} S$ (2) $Na_{2} SO_{3} + SO_{2}$ (3) $Na_{2} S_{2} O_{3} + NaHSO_{3}$ (4) $Na_{2} SO_{3} + H_{2} S$ 147. $Assertion (A) : (SiF_{6})^{2 -} is formed but SiCl62-is not Reason (R) : Electronegativity (EN) of F is higher than EN of Cl$ (1) $Both (A) and (R) are correct and (R) is the correct explanation of (A)$ (2) $Both (A) and (K) are correct but (R) is not the correct explanation of (A)$ (3) $(A) is correct but (R) is not correct$ (4) $(A) is not correct but (R) is correct$ 148. $On combustion of Li, Na and K in excess of air, the major oxides formed, respectively, are$ (1) $Li2O,Na2O2and K_{2} O_{2}$ (2) $Li_{2} O_{2}, Na_{2} O_{2} and K_{2} O_{2}$ (3) $Li2O,Na2O2and KO_{2}$ (4) $Li_{2} O, Na_{2} O and K_{2} O_{2}$ 149. $Assertion (A) : Alkali metals are soft and have low melting and boiling points. Reason (R) : This is because interatomic bonds are weak.$ (1) $Both (A) and (R) are not true$ (2) $(A) is true but (R) is not the correct explanation of (A)$ (3) $(A) is true but (R) is false$ (4) $Both (A) and (R) are true and (R) is the correct explanation of (A)$ 150. $Which of the following is not a disadvantage of using hard water?$ (1) $In production of steam in boilers$ (2) $Formation of scales in cooking utensils$ (3) $In cooking, bathing and washing$ (4) $In ion exchangers$